The harvest rush begins 1 February 2007

Martin Moore is concerned at the danger of rot – and also wondering whether to put more of the wine under screwcap

I returned to the cellar after New Year with a split personality: part of me was still up in the rugged Cedarberg Mountains with its pristine air and sculptured rocks; the other part was raring to hit the cellar and start going!

However, the holidays weren’t all fun. Before I left for the mountains, a live electric wire came down on a neighbouring farm and started a fire that rapidly spread on to our land, destroying part of our olive grove next to the cellar. While inspecting the damage the next day a tick must have dropped from one of the surviving trees in amongst my few remaining hairs, resulting in my spending Christmas day in bed with tick bite fever.

Three on Day One
The first grapes arrived at the cellar on 23 January, about the earliest ever, and then not a lone lorry-load of that earliest of early cultivars Sauvignon Blanc but also Pinotage as well as the grapes from a young Chardonnay vineyard. Three cultivars on Day One! We’ve never had that before (did I hear somebody in the back muttering something about global warming?). With the colour of all the red cultivars deepening rapidly we expect from now on a sustained rush of grapes to the cellar, with very few lulls and a great many bottlenecks. Despite the pressures this rush will bring I, for one, welcome it, for we might then, just for a change, avoid the usual mad scramble to get the last grapes in before the long Easter weekend.

Danger of acetic rot
Unlike fears expressed in some newspaper reports we have as yet had no damage due to the rain of the past month. However, any further rain at this time carries the danger of an outbreak of acetic rot [also known as grey rot or sour rot] in the vineyards of the Winelands. There are two ways this happens: rainwater that collects in the hollows between berries of tightly packed bunches rots the skins that have become thinner as the grapes ripen, while rapid absorption of water through the roots also tends to burst the berries. The end result is the same. The relatively high level of sugar already accumulated in the berries attracts vinegar flies, those carriers of acetic acid bacteria, and from there it is only a short step to acetic rot. Here in the Durbanville Hills area we are lucky in that the southeaster and southwester that blow this time of year dry off the vineyards in quick time keeping them disease-free to a large extent.

These days we are no longer dependent on the rains only as we now have access to an irrigation system that links all our supplier vineyards. However, we are very careful not to over-irrigate just because the water is available. In fact, we prefer to keep the vines under some stress. To ensure we don’t overdo it, every vineyard is inspected daily for telltale signs of overstressing, such as leaves closing up to reduce the area of evaporation.

The endless debate: Cork vs. screw cap
I sometimes think there will never come an end to the ongoing argument as to which is the best closure for wine - cork or screwcaps. Corks have obviously been around for a long time while screwcaps have only been with us for a few decades. According to Jancis Robinson, the Greeks already used corks as stoppers but in the early Middle Ages they disappeared from the scene when the Moors conquered the southern parts of the Iberian peninsula where the main cork forests were (never knew that). Corks only started making a comeback at the beginning of the 17th century.
Portugal has for many years been the dominant cork producer. Growing demand worldwide put supplies under great pressure and quality unavoidably suffered, resulting in a substantial increase in TCA, a chemical compound present in some corks that not only taints the wine but also the reputation of the cork industry. I have written in the past how we as winemakers are obliged to take an extra bottle of each wine to a tasting just in case a bottle is "corked". With such a major export product under threat the Portuguese have fought back, increasing the general quality of their corks and now producing a treated composite cork which they claim is 100% TCA free.

Many winelovers say they would rue the disappearance of the cork as the romantic "pop" when drawn symbolizes for them all the enjoyment of a good bottle of wine. I cannot argue with that. What I can argue with is the notion that wine “breathes” through the cork and that the latter has a beneficial effect on the maturation process. No evidence has ever been found that this is the case. The attraction of the screwcap is the ease of operation and its convenience - if you don’t finish a bottle, you simply screw the cap back on until the next time. Screwcap manufacturers have not rested on their laurels either but have substantially improved the quality of the seal on the inside of the cap. However, recent research claims that in the ageing of red wine screwcaps generate "a whiff of rotten eggs" in the wine through a process called sulphidisation. (I wonder who funded this research!)

The producers of high-quality wines all over the world are nevertheless increasingly switching to screwcaps, primarily for white wines but increasingly for reds too. There is, interestingly, less resistance at the top end of the market where you have more knowledgeable consumers than lower down the price scale. In South Africa several quality producers have changed to screwcaps and others are bound to follow. We use screwcaps for several of our Durbanville Hills wines destined for export. We still haven’t decided whether we will be doing so for the local market. You can help us a lot in coming to a decision by voting and telling us what you prefer. Please click on either of these links to vote in favour or against screwcaps.

• This contribution is extracted, with permision, from the Durbanville Hills January newsletter. Click here for the Durbanville Hills website.